Field of the Invention
The present invention relates to an electron beam irradiation apparatus for treating linear material such as wires e.g. electrical wire, cords and tubes, with electron beams and, particularly to a technique for increasing the work efficiency of an apparatus having a large capacity.
Recently, with the advent of an electron beam accelerator having a high output, for an electron beam radiation apparatus a demand for efficiently treating linear material having various sizes by means of a single accelerator is increasing.
Hitherto, a method has been adopted to provide a plurality of pulley units each having pulleys having a specified size suited to the object to be treated and to replace the pulley units according to the change in size of the object to be treated. This method not only requires a long time delay for replacing the pulley units, but also requires a large investment to provide a lot of pulleys. To solve this problem, apparatuses as shown in FIGS. 5 and 7 in which the irradiation region is divided into two parts is often being used recently.
In FIGS. 5 and 6, a first conventional apparatus of the type described above is shown. It comprises pulley units 7,7' placed in juxtaposition and having a pair of pulleys 5,5 and a pair of pulleys 6,6 which are different in diameter according to different wire sizes of the objects A, B. Each of the pulleys units is placed in each of the divided portions of an irradiation zone 4 (divided into two parts in FIG. 5) irradiated by electron beam 3 which is accelerated and emitted through a window 2 by an electron beam accelerator 1. On the other hand, FIGS. 7 and 8 show another conventional apparatus which is provided with devices 8 such as a beam shutter for interrupting electron beams in order to interrupt the irradiated electrom beam for each divided portion. In these figures, 9 indicates a frame for the pulley units and 10, 10' indicate the drives for the pulley units 7,7'.
The apparatus shown in FIGS. 5 and 6 has a disadvantage in that when there is no longer an object in one divided zone, the whole apparatus has to be stopped, sacrificing the work efficiency. In order to avoid this, it was necessary to control the production resulting in complicating the material flow to balance the work load in each of the divided zones.
With the apparatus shown in FIGS. 7 and 8, when there is no object in one of the divided zones, the whole apparatus may not be stopped by interrupting the electron beams irradiated thereto. But, this cannot avoid the decrease in the work efficiency of the entire apparatus.